I am runing Ubuntu 12.04. I cannot open Ubuntu Software Center and cannot upgrade anything. When I tried to upgrade using terminal with following lines:

sudo apt-get update
sudo apt-get upgrade

My system displayed

Reading package lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/ubuntuarchive.hnsdc.com_ubuntu_dists_s_
precise_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.

2 Answers
2

Open a Terminal (such as gnome-terminal, lxterminal, or xterm). In the default Ubuntu setup, this can be done by pressing the main menu / dash icon, typing "Terminal" and selecting it from the list. After this, type sudo apt-get clean and press Enter. It will ask you for your password, type that (it will not be displayed as you type it) and press Enter. Once it's done, type sudo apt-get update && sudo apt-get dist-upgrade and press Enter. Done.